The invention discloses an energy-saving circulation system for mixing and smashing compound fertilizers. The system comprises two feeding tanks, a material guiding mechanism, a pneumatic mechanism, an outer shell, a vibration mechanism, a crushing mechanism and an air guide pipe, wherein a discharging pipe is arranged at the bottom of the two feeding tanks, and discharging pipes are arranged at the bottoms of the two material tanks; the material guiding mechanism comprises an upper material guiding pipe, a rotating shaft, a plurality of steel rings and a lower material guiding pipe, wherein the upper material guiding pipe communicates with the two discharging pipes to form a Y-shaped pipe; the plurality of steel rings are fixed on the rotating shaft, the lower material guiding pipe is a hose, and a plurality of pairs of material guiding plates are arranged inside the hose from top to bottom at intervals; the pneumatic mechanism comprises a sleeve, a plurality of air blowing pipes, a main air pipe, a booster pump, a hot air blower, wherein the sleeve sleeves the lower material guiding pipe, the plurality of pairs of air blowing pipes penetrating through the side wall of the sleevein a penetrating mode, the main air pipe communicates with the air blowing pipes, and the booster pump arranged on the main air pipe, and the hot air blower communicates with the main air pipe; the vibration mechanism comprises an annular plate, an elastic cushion, a first electric cylinder and a second electric cylinder; the crushing mechanism comprises a cylinder body, a shaft body, a pluralityof blades and a second motor; and the air guide pipe winds around the cylinder body. The energy-saving circulation system for mixing and smashing the compound fertilizers has the beneficial effects that the two fertilizers are not sticky when being crushed and mixed, the mixing is more uniform, and the crushing is more efficient.